U.S. patent application number 16/877125 was filed with the patent office on 2020-09-03 for toilet overflow prevention system and method.
The applicant listed for this patent is LIMIT, INC.. Invention is credited to Josh Fromm, Farshid Salemi Parizi.
Application Number | 20200277772 16/877125 |
Document ID | / |
Family ID | 1000004838419 |
Filed Date | 2020-09-03 |
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United States Patent
Application |
20200277772 |
Kind Code |
A1 |
Salemi Parizi; Farshid ; et
al. |
September 3, 2020 |
TOILET OVERFLOW PREVENTION SYSTEM AND METHOD
Abstract
A system for preventing overflow of a toilet includes a
capacitance sensor arrangement as in combination with certain
features (e.g., flap valve disablement). The system can detect an
overflow flush condition of a toilet by sensing the value of a
parameter of one or more normal flush cycles of the toilet and
establishing a normal range for the value of the parameter using
the sensed value. The system can also store the normal range in a
memory for comparison to a value of the parameter during subsequent
flush cycles. The system can perform sensing over a predetermined
timeframe. The system can include the time frame being sufficient
to include the entire push cycle of the toilet.
Inventors: |
Salemi Parizi; Farshid;
(Seattle, WA) ; Fromm; Josh; (Seattle,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LIMIT, INC. |
Irvine |
CA |
US |
|
|
Family ID: |
1000004838419 |
Appl. No.: |
16/877125 |
Filed: |
May 18, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16017869 |
Jun 25, 2018 |
10697166 |
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16877125 |
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62525645 |
Jun 27, 2017 |
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62688252 |
Jun 21, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E03D 2001/147 20130101;
G01F 23/268 20130101; E03D 11/13 20130101; E03D 5/026 20130101;
E03D 11/00 20130101 |
International
Class: |
E03D 11/00 20060101
E03D011/00; E03D 5/02 20060101 E03D005/02; G01F 23/26 20060101
G01F023/26; E03D 11/13 20060101 E03D011/13 |
Claims
1. A toilet overflow prevention system for use with a toilet,
comprising: a capacitance sensor arrangement configured to emit a
signal indicative of a dielectric constant, said capacitance sensor
arrangement including a first and second conductive plate, said
first conductive plate is disposed above said second conductive
plate; one or more processors configured to: determine a water
height based on said signal indicative of said dielectric constant;
determine an overflow flush condition based on said determined
water height; and generate a control signal in response to
determining said overflow flush condition in order to close a valve
that stops a flow of water within said toilet.
2. The toilet overflow prevention system of claim 1, further
comprising: an actuator configured to receive said control signal
and in response to said control signal, operate to close said valve
that stops said flow of water within said toilet.
3. The toilet overflow prevention system of claim 1, wherein said
valve includes a flapper valve.
4. The toilet overflow prevention system of claim 1, wherein said
one or more processors compares a value of said determined water
height to a normal range of said water height stored in a memory to
make said determination of said overflow flush condition.
5. The toilet overflow prevention system of claim 4, wherein said
one or more processors compares said value of said determined water
height to said normal range over a period of time.
6. The toilet overflow prevention system of claim 5, wherein said
period of time is sufficient to include an entire flush cycle.
7. The toilet overflow prevention system of claim 4, wherein said
one or more processors makes said determination of said overflow
flush condition in response to determining that said value is
continuously outside of said normal range for a period of time.
8. The toilet overflow prevention system of claim 4, wherein said
normal range is preprogrammed.
9. The toilet overflow prevention system of claim 4, wherein said
normal range is determined through a calibration cycle, wherein
said calibration cycle includes said one or more processors
measuring a characteristic of one or more normal flushes, and
determining a normal range above said characteristic.
10. The toilet overflow prevention system of claim 9, wherein said
characteristic is an average peak of the water height during the
one or more normal flushes, and wherein said normal range is above
said average peak of said water height.
11. The toilet overflow prevention system of claim 1, further
comprising a transmitter to transmit said control signal to a
receiver in order to close said valve.
12. The toilet overflow prevention system of claim 1, wherein the
capacitance sensor arrangement further includes a third conductive
plate.
13. The toilet overflow prevention system of claim 1, wherein each
of said first and second conductive plates include a pivot point
configured to enable a degree of rotation.
14. The toilet overflow prevention system of claim 1, wherein at
least one of said first and second conductive plates include a
pivot point configured to enable a degree of rotation.
15. A toilet overflow prevention system for use with a toilet,
comprising: a capacitance sensor arrangement configured to emit a
signal indicative of a dielectric constant, said capacitance sensor
arrangement including a first and second conductive plate, said
first conductive plate is disposed adjacent to said second
conductive plate; one or more processors configured to: determine a
water height based on said signal indicative of said dielectric
constant; determine an overflow flush condition based on said
determined water height; and generate a control signal in response
to determining said overflow flush condition in order to close a
valve that stops a flow of water within said toilet.
16. The toilet overflow prevention system of claim 15, wherein said
one or more processors compares a value of said determined water
height to a normal range of said water height stored in a memory to
make said determination of said overflow flush condition.
17. The toilet overflow prevention system of claim 15, wherein the
capacitance sensor arrangement further includes a third conductive
plate disposed adjacent to at least one of said first conductive
plate or said second conductive plate.
18. A toilet overflow prevention system for use with a toilet,
comprising: a capacitance sensor arrangement configured to emit a
signal indicative of a dielectric constant, said capacitance sensor
arrangement including a first and second conductive plate, said
first conductive plate and said second conductive plate disposed
adjacent to a processor housing; the processor housing that houses
one or more processors, the one or more processors configured to:
determine a water height based on said signal indicative of said
dielectric constant; determine an overflow flush condition based on
said determined water height; and generate a control signal in
response to determining said overflow flush condition in order to
close a valve that stops a flow of water within said toilet.
19. The toilet overflow prevention system of claim 18, wherein said
one or more processors compares a value of said determined water
height to a normal range of said water height stored in a memory to
make said determination of said overflow flush condition.
20. The toilet overflow prevention system of claim 18, wherein the
capacitance sensor arrangement further includes a third conductive
plate disposed adjacent to the processor housing.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
16/017,869 filed Jun. 25, 2018, which claims the benefit under 35
U.S.C. .sctn. 119(e) of U.S. Patent Application No. 62/525,645,
filed Jun. 27, 2017 and U.S. Patent Application No. 62/688,252,
filed Jun. 21, 2018, the disclosure of which is hereby incorporated
by reference herein in its entirety.
BACKGROUND
Field
[0002] The present disclosure generally relates to toilets. More
specifically, the present disclosure relates to an overflow
prevention devices, systems and methods for a toilet.
Description of Related Art
[0003] Although significant advances have been made in toilet
technology, particularly in reducing the amount of water needed for
flushing purposes, a satisfactory solution for preventing the
overflow of a toilet in the event of a blockage of the toilet bowl,
or associated waste plumbing, has not been achieved. Existing
overflow prevention devices, in order to provide acceptable
reliability, are often complex and result in the devices having a
high cost. Furthermore, in order to detect all or nearly all actual
overflow events, some existing overflow prevention devices result
in an undesirable number of false positives--or indications of an
overflow event when one does not actually exist. Thus, a need
exists for improved toilet overflow prevention systems and methods
that address these issues, or at least provide the public with a
useful choice.
SUMMARY
[0004] Preferred embodiments of the present disclosure operate to
prevent toilet overflow in a cost-effective and reliable manner. In
addition, preferred embodiments may be integrated into a toilet
assembly during manufacture or retrofitted into an existing toilet,
preferably with little or no modification of the standard toilet.
Embodiments intended for retrofitting in existing toilets desirably
require a low level of skill to install.
[0005] An aspect of the present disclosure involves a system and
method of preventing toilet overflow utilizing a capacitance sensor
arrangement in combination with certain other system features
(e.g., flap valve disablement) of the present disclosure. In an
optional embodiment, the system and method can utilize a
calibration process substantially as described herein.
[0006] Still another aspect of the present disclosure involves a
method of calibrating a system for detecting an overflow flush
condition of a toilet comprising sensing the value of a parameter
of one or more normal flush cycles of the toilet and establishing a
normal range for the value of the parameter using the sensed value.
The method may also include storing the normal range in a memory
for comparison to a value of the parameter during subsequent flush
cycles. The method may further include the sensing being performed
over a predetermined timeframe. The method may still further
include the time frame being sufficient to include the entire push
cycle of the toilet.
[0007] Another aspect of the present disclosure involves a method
of determining the existence of an overflow flush condition of a
toilet comprising sensing a value of a parameter of a flush cycle
caused by water dynamics within the toilet, comparing the sensed
value of the parameter to a normal range of values for the
parameter and determining that an overflow flush condition exists
if the sensed value is outside of the normal range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features, aspects, and advantages of the
present systems and methods are described in connection with
preferred embodiments of the disclosure, in reference to the
accompanying drawings. The illustrated embodiments, however, are
merely exemplary and are not intended to limit the disclosure. The
drawings include the following figures.
[0009] FIG. 1A illustrates a toilet overflow detection portion of
an embodiment of a toilet overflow prevention system disposed on a
toilet bowl.
[0010] FIG. 1B illustrates capacitance sensing by the overflow
detection portion of the toilet overflow prevention system of FIG.
1A.
[0011] FIG. 2 illustrates a hardware implementation of the toilet
overflow prevention system according to some embodiments.
[0012] FIG. 3 illustrates an exploded view of the overflow
detection portion of the toilet overflow prevention system of FIG.
1A.
[0013] FIGS. 4A and 4B are graphs of normalized voltage values
determined by the sensor portion and relating to water level in the
toilet over time to illustrate the identification of an overflow
condition by the toilet overflow prevention system for two
different toilets.
[0014] FIG. 5A is a graph of normalized voltage difference versus
frequency of oscillation for a toilet overflow prevention system
according to some embodiments.
[0015] FIG. 5B is a graph of normalized voltage difference versus
conductive plate length for a toilet overflow prevention system
according to some embodiments.
[0016] FIG. 5C is a graph of normalized voltage difference versus
distance between conductive plates for a toilet overflow prevention
system according to some embodiments.
[0017] FIGS. 6A and 6B are graphs of normalized voltage value over
time and illustrating a normal flush threshold and an overflow
threshold for a toilet overflow prevention system according to some
embodiments.
[0018] FIGS. 7 and 8 illustrate a tank valve closure device of a
tank portion of the toilet overflow prevention system according to
some embodiments.
DETAILED DESCRIPTION
[0019] The systems and methods disclosed herein that include a
capacitance sensor can be utilized with or without other features
of the systems and methods described herein. For example, the
overall system can comprise the described sensor arrangements
alone, in combination with some or all of the other portions of the
system, or in combination with other components, assemblies or
portions suitable for use with the system. Corresponding methods
are also included. The overall system can utilize the flapper valve
disabling mechanism disclosed herein. Those skilled in the art will
recognize different embodiments made possible by various
combinations of features and methods described herein.
[0020] Neglected toilet overflow can cost thousands of dollars as a
result of mold growth and damage to furniture, upholstery,
electronics, and household appliances. The systems and methods
disclosed herein involve an overflow system configured to detect
such events, preferably prior to an actual overflow from the toilet
bowl. The systems and methods use a novel capacitive sensing
technique that relies on the sizable difference between the
dielectric constants of water and/or air for tracking changes in
water level. The capacitive sensing technique utilizes a sensor
that is outside of the toilet bowl, such that little to no hardware
is required inside the toilet bowl. Furthermore, the capacitive
sensing technique can reduce overall power usage, allowing for
improved operational duration. The capacitive sensing technique can
improve detection of actual overflow conditions while reducing
false positives in comparison to prior art systems.
Overview of Liquid-Level Sensing Techniques
[0021] Optical fiber-based techniques can use fiber optic cables to
measure time-of-flight of an optical signal as it is emitted and
reflected, which is called time-domain reflectometry. This
technique is not well suited for toilets because these techniques
typically require either transparent containers or direct liquid
contact. Standard toilets are made with opaque porcelain, and
direct contact with toilet water raises sanitation concerns.
Thoroughly cleaning dirty toilet overflow prevention systems that
are in direct contact with toilet water can also lead to damage to
the system.
[0022] Mechanical vibration sensors are better suited in situations
where vibration is predictable and always a direct result of liquid
motion, such as in industrial settings. For example, mechanical
vibration-based approaches typically are used when containers are
able to vibrate, such as in pipes or storage tanks. However for
toilets, it has been discovered that users can introduce
unpredictable vibrations that may produce a great deal of noise and
trigger false positives.
[0023] Ultrasonic sensors, like optical sensing, typically use
time-of-flight to estimate liquid-level in pipes and storage tanks.
Ultrasonic sensor electrodes often have to be precisely placed
around the container to properly measure the signal of interest.
Thus, ultrasonic sensors are not well suited to the large variation
in toilet designs. Furthermore, ultrasonic sensors become
prohibitively expensive in certain applications.
[0024] Pressure-sensitive diaphragms can be placed just below the
container or on the exit valve of the container to measure the
liquid level. However, installation can be cumbersome for
applications where the container has already been installed.
Furthermore, pressures sensors are often not viable in situations
without physical contact with the liquid.
[0025] Radio frequency identification (RFID) tags can identify a
dielectric constant of the liquid as a dispersive medium that
changes phase and received signal strength indicator (RSSI).
However, this requires closed loop calibration for precise
measurement. Moreover, radio frequency identification (RFID)
readers can be expensive and bulky.
[0026] Radio Detection and Ranging or Radio Direction and Ranging
(RADAR) techniques can employ time-domain reflectometry or ground
penetration radar-based techniques. RADAR technology may be placed
outside on the container's walls. However, RADAR technology is
typically expensive and requires a significant amount of power.
[0027] Certain toilet prevention systems detect overflow by
detecting water on the floor or that come in contact with
conductivity sensors that are placed on the outside of the bowl.
Such systems suffer from sanitation issues and detect an overflow
event after the water is already out of the bowl and on the
floor.
Capacitance Sensing Technique
[0028] Aspects of the present disclosure relate to technical
solutions using capacitance sensing that can alleviate or address
some or all of the challenges described above. Systems and methods
disclosed herein relate to the detection of water overflow events
in a toilet without requiring and/or minimizing the need to place
sensors inside the toilet bowl. In some embodiments, since direct
contact with the water is not required, the toilet overflow
prevention system using a capacitance sensor arrangement can be
more easily installed and is more sanitary than other systems
described above. The toilet overflow prevention system may also
provide acceptable performance and be easy to install on most
existing toilets, even with variation in toilet design.
Furthermore, the toilet overflow prevention system can reduce power
consumption and can be manufactured with reduced cost compared to
many existing designs.
[0029] FIG. 1A illustrates an embodiment of a toilet overflow
detection portion 100 of an embodiment of a toilet overflow
prevention system disposed on a toilet bowl 110. The detection
portion 100 can include two conductive plates 102A, 102B (or
electrodes), a housing 120, and a battery 122.
[0030] The two conductive plates 102A, 102B of the detection
portion 100 are attached to an exterior surface of the outer
sidewall of the toilet bowl 110, thus not having to be in contact
with the toilet water inside the bowl. One or both of the two
conductive plates 102A, 102B can include one or more degrees of
freedom relative to the housing 120 to allow the plates 102A, 102B
to move (e.g., pivot or rotate) and better conform to the shape of
the individual toilet bowl to which the detection portion 100 is
attached. In other arrangements, the plates 102A, 102B can be
flexible along one or more axes to allow the plates 102A, 102B to
bend and conform or somewhat conform to the shape of the toilet
bowl. Such an arrangement provides the detection portion 100 with
the flexibility to be affixed to various toilet bowl shapes and
sizes. As described at least with respect to FIG. 2, detection
portion 100 can include within or carried by the housing 120 a
suitable sensor to detect a dielectric constant between the two
conductive plates 102A, 102B. The housing 120 can also include an
extension for a battery 122.
[0031] The conductive plates 102A, 102B can be made of a relatively
low-cost and/or readily-available material, such as copper. The
plates 102A, 102B can be in the form of copper plates or copper
tapes. The toilet overflow detection portion 100 can utilize the
two conductive plates 102A, 102B to employ time domain
reflectometry. The toilet overflow detection portion 100 can
determine changes in the static electric field for detecting
changes in a dielectric medium, such as a liquid level. As such,
the toilet overflow detection portion 100 can advantageously reduce
and/or eliminate ambient factors, such as vibration, sound, and
pressure, from interfering with an accurate detection of the water
height or level in the toilet bowl.
[0032] In some embodiments, three or more conductive plates can be
used to detect water height, such as conductive plates 102A, 102B,
102C. For example, three conductive plates each of which are
individually smaller than that of the embodiment with two
conductive plates can be used to be able to measure water height in
a more granular manner while reducing power consumption. In such an
arrangement, the electric field paths between any pair of the
conductive plates may be similar to the field paths as illustrated
in FIG. 1B. Otherwise, the general sensing principle can be the
same as or substantially similar to that described in connection
with the illustrated two-plate arrangement.
Capacitance Sensing of Porcelain, Air, and Water
[0033] FIG. 1B illustrates capacitance sensing by the toilet
overflow prevention system according to some embodiments. The
toilet overflow prevention system can include the toilet overflow
detection portion 100 as illustrated in FIG. 1A.
[0034] The toilet overflow detection portion 100 can detect a
variable dielectric between the two conductive plates 102A, 102B,
utilizing a parallel fringing effect, which includes a fringing
capacitance between the two conductive plates 102A, 102B. The two
conductive plates 102A, 102B can be disposed generally side-by-side
on a substantially similar plane. That is, the side wall of a
toilet bowl is typically curved, but the curve is shallow or has a
relatively large radius of curvature. Thus, when positioned on the
side of the toilet bowl a practical distance apart, the conductive
plates 102A, 102B are generally in a side-by-side arrangement for
the purpose of describing the electric field paths created by the
arrangement.
[0035] The toilet overflow detection portion 100 can detect a
capacitance between the two conductive plates 102A, 102B. As
indicated above, a plurality of electric field paths extends
between the conductive plates 102A, 102B. For example, the toilet
overflow detection portion 100 can detect the capacitance related
to the electric field paths through air (C1) 104A, 104B, through
porcelain (C2) 108A, 108B, 108C, and through water (C3) 106. Since
the conductive plates 102A, 102B are substantially in a parallel
field, the total capacitance between the two plates can include the
electric field path through porcelain 108C, through water 106,
through air 104A, and through the porcelain 108A. Because the shape
and material of the toilet is constant, the measurable variation in
capacitance can be described as a function of the water height
inside the bowl. Although humidity and other factors may have some
effect, the dielectric constant of water is much higher than that
of porcelain and air that the humidity and other factors can be
negligible. For example, the dielectric constant of water can be
roughly a factor of 80, whereas the porcelain can be a factor of 6
and air a factor of 1. Thus, measuring the capacitance between the
conductive plates 102A, 102B can be substantially associated with
the height of water in the toilet bowl 110. The measured
capacitance, C.sub.water, C.sub.air, and C.sub.porcelain can be
represented by:
C water = 0 w A h w ##EQU00001## C air = 0 a A h a ##EQU00001.2## C
porcelain = 0 p A h p ##EQU00001.3##
where h.sub.w can represent the height of the water in the bowl,
h.sub.a can represent the height of the air in the bowl from the
top plate, and h.sub.p can represent the thickness of the
porcelain. .epsilon..sub.w, .epsilon..sub.a, and .epsilon..sub.p
can represent the relative permittivity of water, air, and
porcelain, respectively. .epsilon..sub.0 can represent the
permittivity of free space, and A can represent the area of the
electrodes.
[0036] Because the dielectrics can be stacked serially, the total
capacitance can be represented by:
C 3 = 1 1 C porcelain + 1 C water + 1 C air + 1 C porcelain
##EQU00002## C 3 = 0 w a A C porcelain C porcelain ( D w - h w ( w
- a ) ) + 2 0 w ? A ##EQU00002.2## ? indicates text missing or
illegible when filed ##EQU00002.3##
where D can represent the distance between the conductive plates
102A, 102B.
[0037] However, since .epsilon..sub.w can be much larger than
.epsilon..sub.0, .epsilon..sub.w can be small and negligible. Thus,
the total capacitance can be represented by:
C 3 = .alpha. C porcelain C porcelain ( D - h w ) + 2 .alpha.
##EQU00003##
[0038] Since C.sub.porcelain and .alpha. can be constant, the
effective capacitance of the toilet overflow detection portion 100
can vary due to the change in the height of water. As the height of
the water (h.sub.w) increases, C3 also increases and therefore the
total capacitance between the two plates increases, allowing more
AC current to pass from one conductive plate 102B to the other
conductive plate 102A, and/or vice versa.
Illustrative Hardware Implementation of Toilet Overflow Prevention
System
[0039] FIG. 2 illustrates a hardware implementation of the toilet
overflow prevention system according to some embodiments. The
toilet overflow prevention system can include the toilet overflow
detection portion 100 as illustrated in FIGS. 1A and/or 1B.
[0040] The toilet overflow prevention system can include a sensing
unit 201 and a tank unit 215. The overflow detection portion 100
can consist of or can include the sensing unit 201. The sensing
unit 201 can include a square wave generator 202, a first low pass
filter 204, a rectifier 206, a second low pass filter 208, an
analog-to-digital converter 210, an overflow detector 212, a
transmitter 214, conductive plates 102A, 102B, and/or a housing
120. The tank unit 215 can include a receiver 216, a highside
switch 218, and/or a solenoid 220.
[0041] The square wave generator 202 can generate a square wave to
be transmitted from a first conductive plate 102A to be received by
a second conductive plate 102B or vice-versa. The generated signal
can be an AC signal sent to one of the conductive plates 102A. The
square wave can be excited by a voltage source, such as a 5 volt
source, and be characterized by a duty cycle and a frequency, such
as a 50% duty cycle square wave at 100 kHz. As such, the toilet
overflow detection portion 100 can reduce the average power
consumption based on the generated square wave.
[0042] The received signal can be filtered using the first low pass
filter 204, rectified using the rectifier 206, filtered using the
second low pass filter 208, converted to a digital signal by
sampling the signal using the analog-to-digital converter 210, and
assessed to determine whether an overflow condition has occurred
and/or is impending by the overflow detector 212. One example
method of the assessment to determine whether an overflow condition
has occurred and/or is impending is described further below.
[0043] If it is determined that an overflow condition has occurred
and/or is impending, the toilet overflow prevention system can
respond to the overflow condition, such as by shutting off water
flow from the tank to the bowl. For instance, the overflow
detection portion 100 can transmit a signal to the tank unit 215
using a transmitter 214 to activate the shut-off mechanism. The
tank unit 215 can receive the signal using a receiver 216, turn on
the highside switch 218, and activate the solenoid 220 which can
initiate a process or actuate a mechanism to stop the flow of
water, such as by closing a flapper valve 222 of the toilet. A
small solenoid 220 can be added to the toilet tank to close the
flapper valve 222 and prevent additional water from entering the
toilet bowl 114. Once the flapper valve 222 is closed, the user can
address the issue causing the overflow. Once the user alleviates
the overflow condition, a signal can be transmitted to the tank
unit 215 to switch off the switch 218 and deactivate the solenoid
220.
Illustrative Exploded View of Toilet Overflow Prevention System
[0044] FIG. 3 is an exploded view of the toilet overflow detection
portion 100 as illustrated in FIGS. 1A, 1B, and 2. The toilet
overflow detection portion 100 can include conductive plates 102A,
102B, a pivoting housing 304A, 304B, a sensor housing 120A, 120B, a
printed circuit board (PCB) 302, and a battery 122.
[0045] As described above, the conductive plates 102A, 102B can be
or include a copper material. In the illustrated arrangement, the
conductive plates 102A, 102B are or include a copper foil tape.
Each one of the conductive plates 102A, 102B can be attached to or
carried by a movable portion of the detection portion 100, which
can be one of a pair of the pivoting housings 304A, 304B. Each of
the pivoting housings 304A, 304B can move (e.g., pivot) relative to
the sensor housing 120A to allow the detection portion 100 to
adjust and conform to various toilet designs. In some embodiments,
each of the pivoting housing 304A, 304B can include a hinge that
allows for pivoting of the pivoting housing 304A, 3304B with
respect to the sensor housing 120 along the hinge. In some
embodiments, the pivoting housing 304A, 304B can include other
mechanisms to conform to various toilet designs, such as a
plurality of hinges, a malleable surface, a hinge located in a
different location, a lock, a fastening mechanism, and/or the
like.
[0046] The sensor housing 120A, 120B can house the PCB 302 that
senses the dielectric constant across the conductive plates 102A,
102B. As will be appreciated by those skilled in the art, the PCB
302 can include the hardware and software components as shown in
and described in connection with FIG. 2 or that are otherwise
necessary or desirable to carry out the overflow detection and/or
prevention methodology described herein. For example, the PCB 302
can include a memory 301 and a processor 303. The sensor housing
120A, 120B can house other parts of the toilet overflow detection
portion 100, such as the battery 122, the conductive plates 102A,
102B, wiring (not shown), and/or the like.
Toilet Overflow Prevention System Overflow Condition
Identification
[0047] FIGS. 4A and 4B are graphs 400, 450 that illustrate the
determination of an overflow condition in two different toilets by
the toilet overflow prevention system according to some
embodiments. The toilet overflow prevention system can produce an
analog signal that correlates to the level of water in the toilet
bowl. However, given the vast variation in toilet bowl design and
shape, the movement of water in the toilet bowl during a flush and
during clogging can also vary. As such, the toilet overflow
prevention system can detect water flow signatures over time to
differentiate between an overflow condition and a normal flush.
[0048] In addition or in the alternative, the toilet overflow
prevention system can be calibrated for the particular toilet on
which it is installed. The calibration process can occur during
manufacture of the toilet overflow prevention system, such as
during manufacture of the toilet overflow detection portion 100.
For example, such a calibration process could take into account the
broad category of toilet type, toilet brand, toilet model, bowl
shape or other relevant factor (e.g., country or region
designations). Thus, different models of the system could be sold
or the system could utilize a suitable user interface to allow
selection of an appropriate calibrated mode of operation. However,
the calibration process preferably occurs after installation on a
specific toilet with which the system will be used. The calibration
can be conducted after installation and before normal usage of the
toilet. For example, the user could be instructed to conduct
multiple flushes in succession to execute the calibration process.
In other arrangements, the calibration process can occur over the
first several normal flush cycles of the toilet. In other words,
the user will simply commence regular use of the toilet after
installation of the system and the system will utilize a number of
the subsequent flushes to calibrate itself to the toilet.
[0049] As illustrated in the graphs 400 and 450 of FIGS. 4A and 4B,
the user and/or the toilet overflow prevention system can perform
calibration by initiating one or more normal flushes, such as the
normal flushes 402, 404, 406, 452, 454. Based on a characteristic
signature of the toilet bowl water for a normal flush 402, 404,
406, 452, 454, the toilet overflow prevention system can determine
a threshold and/or rules for determining a water overflow condition
408, 456. As described above, in some embodiments, the user can
manually perform one or more normal flushes in succession as part
of the calibration process. Or, in some embodiments, the toilet
overflow prevention system can automatically identify the one or
more normal flushes during normal use and/or automatically perform
self-calibration during normal use.
[0050] A water overflow condition 408, 456 can be determined based
on any suitable characteristic(s) of the flush signature. For
example, a water overflow condition 408, 456 can be based in whole
or in part on the magnitude of the sensed voltage (which preferably
relates to water level) and/or the duration of a voltage peak. As
illustrated in FIG. 4A and FIG. 4B, the duration of the toilet bowl
water above a certain threshold as indicated by the normalized
voltage value can be useful in distinguishing normal flushes from
overflow conditions. For example, the width of the normal flushes
402, 404, 406, 452, 454 can be significantly shorter than a water
overflow condition 408, 456 as shown in the graphs, which
corresponds to shorter time periods for a normal flush 402, 404,
406, 452, 454 versus an overflow condition 408, 456. In addition or
in the alternative, the water overflow condition 408, 456 can be
based on the magnitude of the water height. For example, as
illustrated in FIG. 4A and FIG. 4B, a water overflow condition 408,
456 has a much higher peak than the normal flushes 402, 404, 406,
452, 454 for the same toilet.
[0051] The system can utilize the normal flush information to
identify characteristics that can be used to for comparison with
future flush events to accurately identify overflow conditions.
Such characteristics can be or include, for example, averages or
maximum values of the normal flushes. For example, an average peak
voltage of a normal flush and/or an average duration of a normal
flush can be determined. Based in this determination, the system
can determine a normal flush threshold, an overflow threshold,
and/or set of criteria (referred to herein as a "threshold" for
convenience) for determining the existence of an overflow condition
408, 456. The threshold can be predefined (e.g., a particular
increase in the peak voltage and/or duration relative to the
average value). The threshold can remain constant after the initial
calibration or can be reassessed over time. For example, the system
can keep a running average of peak voltage and/or duration, or
could conduct an automatic calibration update after a particular
period of time to take into account changes in environmental or
other factures that could have an impact on the values determined
during the initial calibration. The overflow threshold can be set
to a value above the normal flush threshold, such as a particular
value above or a percentage above the normal flush threshold.
[0052] In some embodiments, the slope of the change in water level
and/or other derivative of the water level can be used to determine
an overflow condition. If the slope of the water level is
increasing, a state machine can consider the current state a
"rising state" of toilet water level. If the slope of the water
level is decreasing, the state machine can consider the current
state a "peak" state during the transition and/or a "falling" state
thereafter if the negative slope continues. During the "peak
state," the toilet overflow prevention system can track how long
the water level is at the "peak state" such as by utilizing a
timer. If the water is at a "peak state" for a period of time
beyond a certain threshold, the toilet overflow prevention system
can set an overflow condition. If the water level falls below the
water level for the "peak stake" or a threshold based on the water
level for the "peak stake," the toilet overflow prevention system
can set a non-overflow condition.
[0053] In some embodiments, if the toilet overflow prevention
system misses an overflow condition based on the rise of the water,
the toilet overflow prevention system can identify the overflow
condition hereafter when the water continues to rise and/or rises
above both conductive plates 102A, 102B. Then, the toilet overflow
prevention system can identify a large water height measurement,
providing another opportunity to identify an overflow water
condition.
[0054] In some embodiments, the water overflow condition 408, 456
can be determined based on optimization of accuracy of water
overflow conditions and/or minimizing false positives. Missing a
water overflow condition and/or false positives can result in
costly overflow or requiring users to manage a system that is
connected to a toilet that is not currently in an overflow
condition, respectively. It is desirable to reduce or minimize the
incident of false positives to limit or eliminate user annoyance in
having to unnecessarily reset the system.
[0055] In order to reduce power consumption, the toilet prevention
overflow system can check the water level voltage periodically,
such as once every 0.1 seconds. In some embodiments, the toilet
prevention overflow system can vary the frequency of the check,
such as checking more often when the water voltage level meets a
certain threshold.
Frequency Oscillation Optimization for Toilet Overflow Prevention
System
[0056] FIG. 5A illustrates a graph 500 for frequency oscillation
optimization for a toilet overflow prevention system according to
some embodiments. The graph illustrates oscillation frequencies
that excite a conductive plate to be received by another conductive
plate after propagating through a toilet structure, such as
porcelain. The graph 500 for frequency oscillation optimization
illustrates oscillation frequency and a measure of the dielectric
constant.
[0057] As illustrated in graph 500 for frequency oscillation
optimization, as the frequency increases, the normalized
analog-to-digital converter value (the dielectric constant)
increases due to enhanced coupling, up to a certain frequency and
decreases thereafter, due to worsened coupling. For example in a
particular toilet bowl design, as the frequency oscillation
increases 502, 504, 506, 508, the normalized voltage difference
increases, and as the frequency oscillation increases thereafter
510, 512, the normalized voltage difference decreases. As such, the
toilet overflow prevention optimization can determine an optimal
frequency for varying toilet bowls based on normalized voltage
difference measurements across various frequency oscillations.
[0058] In some embodiments, the selection of frequency oscillation
can be based on one or more factors, such as the normalized voltage
difference in the dielectric constant, or power consumption. The
selection of frequency oscillation can be based on the frequency
oscillation that provides the smallest power consumption among a
list of frequency oscillations that meets a certain voltage
difference threshold. For example, if the threshold is a normalized
voltage difference is 0.15, then the frequencies of oscillation
502, 504, 506, 508, 510, 512 all meet the threshold. As such, the
frequency (100 kHz) with the smallest power consumption 502 can be
selected. If the normalized voltage difference is higher, the
detection portion 100 may be able to detect overflow conditions
with enhanced resolution. However if the normalized voltage
difference is above a certain threshold, the resolution of
detecting overflow conditions may not be significant, and as such,
the reduction of power consumption may become more important. In
some embodiments, the preferred frequency is 100 kHz. The selection
of frequency oscillation can be factory set or can form part of the
calibration process.
Conductive Plate Length Optimization for Toilet Overflow Prevention
System
[0059] FIG. 5B illustrates a graph 530 for conductive plate length
optimization for a toilet overflow prevention system according to
some embodiments. The graph 530 for conductive plate length
optimization illustrates the relationship between the length of
each conductive plate and the normalized voltage difference of the
dielectric constant.
[0060] In the example of the graph 530, with increased length of
each conductive plate, 532, 534, 536, 538, the normalized voltage
difference between the conductive plates increase because the
capacitance can be a function of the plate area resulting in an
increased observable capacitance between the conductive plates. In
some embodiments, the determination of the size of the conductive
plates can be based on a factor that affects the size of the
capacitive area for the conductive plates, such as the width, the
shape, the thickness, and/or the like. When the length of each
conductive plate increases, the conductive plate area increases,
thus resulting in a larger difference between the signals at the
conductive plates. In some embodiments, after a certain threshold
normalized voltage difference is met, a relatively small or the
smallest length of the conductive plates can be selected because of
size considerations, such as for smaller packability of the overall
detection portion of the toilet overflow system and/or the ease of
conforming to various toilet shapes and designs. In some
configurations, the conductive plates 102A, 102B have dimensions of
about 1-1.5 inches by about 1-1.5 inches, or about 1.25 by about
1.25 inches.
[0061] In some embodiments, the length of the conductive plate can
be based on one or more factors, such as a desired normalized
voltage difference and/or the overall size of the toilet overflow
prevention system.
Distance Between Conductive Plates Optimization for Toilet Overflow
Prevention System
[0062] FIG. 5C illustrates a graph 560 for distance between
conductive plates optimization for a toilet overflow prevention
system according to some embodiments. The graph 560 illustrates the
relationship between the distance between the two conductive plates
562, 564, 566, 568, 570 and the normalized voltage difference of
the dielectric constant.
[0063] If the distance between the two conductive plates is small,
the coupling for the two conductive plates can take more weight in
the capacitance value because the path across the air between the
two electrodes gets more AC voltage and can have more weight than
the difference that is generated by the change in the water level.
If the distance between the two conductive plates is large, the
coupling between the two conductive plates can have less weight and
thus, the total capacitance can become smaller, making it harder to
differentiate between idle water levels and flush water levels.
[0064] In some configurations, a distance between the conductive
plates 102A, 102B is between about 1-2 inches, or about 1.5 inches.
In some embodiments, the distance between the conductive plates can
be based on the size and/or the length of the conductive plates.
For example, larger conductive plates may provide increased
observed capacitance, and as such, the distance between the
conductive plates may not have to be as large as that for smaller
conductive plates for detection of overflow conditions.
Normal and Overflow Thresholds for Toilet Overflow Prevention
System
[0065] FIGS. 6A and 6B illustrate graphs 600, 650 for normal flush
and overflow thresholds for a toilet overflow prevention system
used in a first and second toilet design, respectively, according
to some embodiments. The graphs 600, 650 illustrate that the
thresholds can be different between different toilets. As described
herein, the thresholds can differ as a result of the calibration
process. The graphs 600, 650 illustrate overflow thresholds 602,
652 and normal flush thresholds 604, 654. The normal flush
thresholds 604, 654 can be determined by taking an average peak of
the voltage values for normal flushes during a calibration period,
such as the normal flush thresholds described for FIGS. 4A-4B. In
some embodiments, the toilet overflow prevention system can
determine an overflow condition if the voltage is above the normal
flush thresholds 604, 654 over a period of time.
[0066] As shown in the graphs 600, 650, an overflow threshold 602,
652 can be higher than a normal flush threshold 604, 654. The
overflow threshold 602, 652 can be a predetermined amount or a
percentage above the normal flush threshold 604, 654, such as the
overflow thresholds described with respect to FIGS. 4A-4B.
[0067] The graphs 600, 650 illustrate five states: no event, a
shower event, a normal flush, a user sits on the toilet event, and
an overflow condition. As illustrated, during a normal event, a
shower event, and a user sits on toilet event, the water level does
not rise near the normal flush threshold. During a shower event,
some systems can be affected by condensation formed on the
conductive plates as steam builds up in confined spaces leading to
bigger spikes in measured voltage. However, the toilet overflow
prevention system was not affected by a shower event. During a
normal flush, the water levels increase closer to the normal flush
threshold 604, 654 and/or exceed the normal flush threshold 604,
654, but do not meet the overflow threshold 602, 652. During an
overflow condition, the normalized voltage difference meets the
overflow threshold 602, 652.
Implementation of a Toilet Overflow Prevention System
[0068] FIGS. 7 and 8 illustrate an example actuator 700 according
to some embodiments. The actuator 700 can be or include the
solenoid device 220 shown in and discussed in connection with FIG.
2. The actuator 700 is generally configured to be attachable to an
overflow tube of a toilet, such as the overflow tube 756. As
discussed in connection with FIG. 2, the actuator 700 preferably is
capable of receiving a signal sent by the overflow detection
portion 100. The actuator 700 is generally configured to forcibly
close the flapper valve 738 so as to inhibit or entirely stop the
flow of water through the passage from the tank to the toilet bowl.
In the particular embodiment illustrated in FIG. 7 and FIG. 8, the
actuator 700 is configured to push down the flapper valve 738 via a
weight dropping mechanism, which is discussed in greater detail
below.
[0069] The actuator 700 includes a main housing 702 that preferably
is a generally tubular member that houses, at least in part, an
inner hammer rod 704 and an outer hammer rod 706. The inner hammer
rod 704 and the outer hammer rod 706 are configured to be axially
movable within the main housing 702. The inner hammer rod 704
carries a hammer weight 708 that is attached to the lower end of
the inner hammer rod 704. The main housing 702 also includes an
overflow tube attachment structure 710 that allows the actuator 700
to be secured to the top of the overflow tube 756 so as to position
the actuator 700 above the flapper valve 738.
[0070] With continued reference to FIG. 7, the upper portion of the
main housing 702 preferably includes a solenoid assembly 712 that
is configured to selectively restrain or release the outer hammer
rod 706, which in turn restrains or releases the hammer weight 708.
The solenoid assembly 712, in some embodiments, comprises a
solenoid 714 that is connected to a solenoid latch 716 that defines
a mechanical catch to hold or release the outer hammer rod 706. As
discussed briefly above, the solenoid 714 can be actuated by a
control signal that may be sent by the sensor or processor. The
solenoid 714 may receive a control signal via a hardwired signal or
a wireless signal, such as an RF signal, for example.
[0071] The actuator 700 preferably is configured to hold the hammer
weight 708 in an elevated position relative to the flapper valve
738 such that the flapper valve 738 is free to move between its
open and closed positions during normal flush cycles. In the
illustrated embodiment, after the actuator 700 has received an
appropriate control signal, the solenoid 714 activates the solenoid
latch 716 to release the outer hammer rod 706. As a result, the
outer hammer rod 706, and thus the hammer weight 708, are released
and fall downward under their own weight to forcibly close the
flapper valve 738. The detection, processing and release of the
hammer rod 706 preferably occurs before the entire flush volume of
water is evacuated from the tank.
[0072] The actuator 700 preferably is configured to have a
predetermined amount of stroke for the outer hammer rod 706
relative to the main housing 702. That is, the outer hammer rod 706
generally determines the amount of movement that the hammer weight
708 will have based on the length of the outer hammer rod 706 and
the length of the main housing 702. In some embodiments, it is
preferable that the hammer weight 708 will be lowered to a
sufficient height so as to securely close the flapper valve 738. In
the illustrated embodiment, a certain amount of telescopic
adjustability is provided between the inner hammer rod 704 and the
outer hammer rod 706.
[0073] With continued reference to FIG. 7, the inner hammer rod 704
preferably is insertable into the outer hammer rod 706 and
telescopically adjustable so as to adjust the height of the hammer
weight 708 relative to the height of the overflow tube 756. The
inner hammer rod 704 preferably is securable relative to the outer
hammer rod 706 by a rod collar 718 that can be tightened to secure
the inner hammer rod 704 in a desired position relative the outer
hammer rod 706. Such an arrangement allows for adjustment to
various toilet designs.
[0074] Also included in the actuator 700 is a reset latch 720 that
is configured to be manually lifted to reset the actuator 700 after
the hammer weight 708 has been released by the solenoid latch 716.
As will be appreciated by one skilled in the art, in other
embodiments, the actuator 700 can be configured to automatically
reset after the hammer weight 708 has been released, thus negating
the need for the reset latch 720.
[0075] With reference to FIG. 8, the actuator 700 is secured to the
top of the overflow tube 756 via the overflow tube attachment
structure 710, which is configured to be a snap-fit in the
illustrated arrangement. Furthermore, the main housing 702 of the
actuator 700 preferably is positioned such that the hammer weight
708 is located generally above the flapper valve 738 such that when
the hammer weight 708 is released, it will drop on the top of the
flapper valve 738 and forcibly close the flapper valve 738.
[0076] With continued reference to FIG. 8, the hammer weight 708 is
shown being supported in a height set jig 722 which is configured
to allow a user to set the height of the hammer weight 708 relative
to the outer hammer rod 706 (and the flapper valve 738). After the
actuator 700 has been installed on the overflow tube 756, a user
preferably loosens the rod collar 718 thus allowing the inner
hammer rod 704 to move axially relative to the outer hammer rod
706. At this time it is preferable that a user place the hammer
weight onto the top of the height jig 722 wherein the legs 724 of
the height jig 722 are resting on the bottom of the tank. At this
time while the hammer weight 708 is being supported by the height
jig 722, a user then preferably tightens the rod collar 718 to
secure the inner hammer rod 704 relative to the outer hammer rod
706 thus setting the proper height of the hammer weight 708. Before
the system is placed into use, the height jig 722 preferably is
removed.
[0077] Although one particular embodiment of the actuator 700 has
been illustrated with reference to FIG. 7 and FIG. 8, as will be
appreciated by one skilled in the art, various other embodiments of
actuators can be used to substantially reduce or eliminate water
flow to the bowl in the event of a detected overflow flush
condition. Such suitable alternative embodiments may comprise an
actuator 700 that independently rests on the bottom of the tank and
does not attach to the overflow tube 756. Other suitable
embodiments may comprise an actuator that is attached to the upper
rim of the tank. Another suitable embodiment may comprise a
rotational solenoid attached to the flapper valve 738 such that a
torsional force is applied to the pivoting arm of the flapper valve
738 so as to close the flapper valve in the event of an overflow
flush condition. Another embodiment may not comprise an actuator
located in the tank but may include an actuator that is attached a
valve that controls water flow from the external water supply
source for the toilet. Thus, the actuator 700 shown in FIG. 7 and
FIG. 8 is simply one possible embodiment of an actuator that can be
used with the toilet overflow prevention system.
[0078] Although the systems and methods have been disclosed in the
context of certain preferred embodiments and examples, it will be
understood by those skilled in the art that the present disclosure
extends beyond the specifically disclosed embodiments to other
alternative embodiments and/or uses of the systems and methods and
obvious modifications and equivalents thereof. In addition, while
the number of variations of the systems and methods have been shown
and described in detail, other modifications, which are within the
scope of this disclosure, will be readily apparent to those of
skill in the art based upon this disclosure. It is also
contemplated that various combinations or subcombinations of the
specific features and aspects of the embodiments may be made and
still fall within the scope of the disclosure. Accordingly, it
should be understood that various features and aspects of the
disclosed embodiments can be combined with, or substituted for, one
another in order to perform varying modes of the disclosed systems
and methods. Thus, it is intended that the scope of the present
disclosure herein disclosed should not be limited by the particular
disclosed embodiments described above, but should be determined
only by a fair reading of the claims.
* * * * *